Conversion apparatus, radiation detecting apparatus, and radiation detecting system

ABSTRACT

A conversion apparatus of the present invention includes a pixel region in which a plurality of pixels are arranged. The pixels are including the switching elements and the conversion elements. The pixel region includes a switching element region in which the plurality of switching elements are arranged in row and column directions, and a conversion element region in which the plurality of conversion elements are arranged in row and column directions. A plurality of signal wirings are including a second metal layer, and connected to the plurality of switching elements of the column direction. Bias wirings are including a fourth metal layer, and connected to the plurality of conversion elements. An external signal wiring is including the first metal layer outside the pixel region, and connected to the signal wirings. The external signal wiring and the bias wiring intersect each other.

TECHNICAL FIELD

The present invention particularly relates to a conversion apparatusapplied to a medical image diagnosis apparatus, a non-destructiveinspection apparatus, an analyzer using radioactive rays, or the like, aradiation detecting apparatus using the conversion apparatus, and aradiation detecting system. In the description, electromagnetic waves ofvisible lights or the like, X-rays, α-rays, β-rays, γ-rays, and the likeare included in the radioactive rays.

BACKGROUND ART

Conventionally, radiography used for medical image diagnosis has beenclassified into general radiography such as X-ray radiography forobtaining a static image, and fluoroscopic radiography for obtaining amoving image. Each radiography including a imaging apparatus and animage pickup apparatus are selected as occasion demands.

In the conventional general radiography, two systems described belowhave mainly been implemented.

One is a screen film imaging (abbreviated as SF imaging hereinafter)system which executes imaging through film exposure, developing, andfixing by using a screen film prepared by combining a fluorescent screenand a film. The other is a computed radiography imaging (abbreviated asCR imaging hereinafter) system which records a radioactive ray image asa latent image in an photostimulable phosphor, scans the acceleratedphosphorescence fluorescent material with a laser to output opticalinformation according to the latent image, and reads the output opticalinformation by a sensor. However, in the conventional generalradiography, there has been a problem in that a process of obtaining theradioactive ray image is complex. The obtained radioactive ray image canbe converted into digital data, but it is indirectly digitized. Thus,there arises a problem in that it takes much time to obtain digitizedradioactive ray image data.

Next, in the conventional fluoroscopic radiography, an image intensifierradiography (abbreviated as I. I. radiography hereinafter) system thatuses a fluorescent material and an electron tube has mainly beenemployed. However, in the conventional fluoroscopic radiography, therehas been a problem in that an apparatus is large-scaled because of useof the electron tube. The use of the electron tube has createddifficulty in obtaining an image having a large area because of a smallfield of view (detection area). Furthermore, there has been a problem inthat a resolution of an obtained image is low because of the use of theelectron tube.

Thus, in recent years, attention has been focused on a sensor panelconfigured by arranging, in a 2-dimensional matrix, a plurality ofpixels having conversion elements and switch elements for convertingradioactive rays or lights from fluorescent materials into charges. Inparticular, attention has been focused on a flat panel detector(abbreviated as FPD hereinafter) in which a plurality of pixels havingconversion elements prepared by, on an insulating substrate, non-singlecrystal semiconductors such as amorphous silicon (abbreviated as a-Sihereinafter) or the like, and thin-film transistors are arranged(abbreviated as TFT hereinafter) prepared by non-single crystalsemiconductors in a 2-dimensional matrix.

This FPD can obtain an electric signal based on the image information byconverting, by the conversion element, radioactive rays having imageinformation into charges, and reading the charges by the switch element.Accordingly, the image information can be directly taken out as digitalsignal information from the FPD, so handling of image data such asstorage, processing, and transfer is facilitated to enable further useof the radioactive ray image information. Characteristics such assensitivities of the FPD depend on radiography conditions. As comparedwith the conventional SF or CR imaging system, however, equal or bettercharacteristics have been verified. Additionally, as the electric signalhaving the image information can be directly obtained from the FPD, ascompared with the conventional SF or CR imaging system, there is anadvantage that time necessary for obtaining an image is shortened.

As the FPD, as described in International Application Publication No.WO93/14418, a PIN type FPD has been known which uses a sensor panelconfigured by arranging, in a 2-dimensional matrix, a plurality ofpixels formed of PIN type photodiodes made of a-Si and TFTs. Such thePIN type FPD has a laminated structure in which a layer constituting aPIN type photodiode is disposed on a layer constituting the TFT on asubstrate. As described in U.S. Pat. No. 6,075,256, an MIS type FPD hasbeen known which uses a sensor panel configured by arranging, in a2-dimensional matrix, a plurality of pixels formed of MIS typephotosensors made of a-Si and TFTs. Such the MIS type FPD has a planestructure in which the MIS type photosensor is disposed by the samelayer configuration as that constituting the TFT on the substrate.Furthermore, as described in U.S. Application Publication No.US-2003-0226974, an MIS type FPD of a laminated structure has been knownin which a layer constituting the MIS type photosensor is disposed onthe layer constituting the TFT on the substrate.

The above-mentioned FPD will be described below by taking the example ofU.S. Application Publication No. US-2003-0226974 with reference to thedrawings. For simpler explanation, an example of an FPD arranged at a3×3 2-dimensional matrix will be taken.

FIG. 6 is a schematic equivalent circuit diagram showing an equivalentcircuit of a conventional FPD described in U.S. Application PublicationNo. US-2003-0226974. FIG. 7 is a schematic plan diagram of one pixel ofthe conventional FPD described in U.S. Application Publication No.US-2003-0226974. FIG. 8 is a schematic sectional diagram cut on the line8-8 of FIG. 7.

By the FPD configured as described above, light emitted from awavelength converter according to incident radioactive rays areconverted into signal charges by a plurality of photoelectric conversionelements to which photoelectric conversion biases have been applied. Aplurality of switching elements perform transfer operations according toa drive signal applied to the drive wiring by a drive circuit, wherebythe signal charges converted by the photoelectric conversion elementsare transmitted through a signal wiring to be read in parallel to asignal processing circuit. The signal charges read in parallel areconverted into serial signals by the signal processing circuit, andconverted from analog signals into digital signals by an A/D converterto be output. Through the above operation, it is possible to obtain animage signal of one pixel according to the incident radioactive rayscontaining image information.

In intersection portions of the FPD having the above laminatedstructure, the wirings are insulated from each other via the insulatinglayers. However, as reliabilities at the intersection portions aregreatly affected by manufacturing yield or image quality, insulatingproperty is highly required among the wirings. In particular, signalcharges generated by the photoelectric conversion element andtransferred by the switching element flow to the signal wiring. Thus,leakage between the signal wiring and another wiring totally reduces aquality of the FPD. Further, the influence of parasitic capacitance orwiring resistance of the signal wiring causes noise of an image signalto be output, creating a possibility of adversely affecting the imagesignal. In particular, the radiation detecting apparatus which outputssignal charges by a small exposure radiation dosage and must have a highsensitivity, as a noise influence is large because of small signalcharges generated by the photoelectric conversion element, it isnecessary to reduce the influence of parasitic capacitance or wiringresistance of the signal wiring. Consequently, it is necessary to secureinsulation at the intersection portion of the signal wiring and thedrive wiring, and insulation at the intersection portion of the signalwiring and a bias wiring, which cause parasitic capacitance in thesignal wiring. It is particularly necessary to secure insulation betweenthe signal wiring and the bias wiring. In addition, it is required toreduce the parasitic capacitance or wiring resistance. Reasons for thiswill be described below.

As described above, a first insulating layer, a first semiconductorlayer, and a first impurity semiconductor layer similar to those usedfor the switching element are present between the wirings at theintersection portion of the signal wiring and the drive wiring at theintersection portion. As these layers are formed in the process offorming the switching element, layer quality is high, and the firstinsulating layer exhibits very high insulating property because it isused for the gate insulating film of the switching element. Thus, as theinsulating property is high between the signal wiring and the drivewiring at the intersection portion, the drive wiring is formed thick andthe wiring width is narrowed so as to reduce the influence of parasiticcapacitance, whereby the influence of noise can also be reduced. On theother hand, an interlayer insulating layer, a second insulating layer, asecond semiconductor layer, and a second impurity semiconductor layerare present between the signal wiring and the bias wiring at theintersection portion. As these layers are formed after the switchingelement is formed, a forming temperature thereof must be lower than anendurance temperature of the switching element. Generally, since theendurance temperature of the switching element is lower than the formingtemperature, the interlayer insulating layer formed in an upper layerthereof is formed at a temperature lower than that of the firstinsulating layer. Even when an inorganic material similar to that of thefirst insulating layer is used for the interlayer insulating layer, itsinsulation is low due to the low forming temperature. Even when anorganic material also serving as a planarized film is used, althoughdifferent from the case of the first insulating layer, to form theinterlayer insulating film its insulating property is lowered as theorganic material has lower insulating property compared to that of theinorganic material in most cases. When the MIS type photosensor is used,the second insulating layer that can be made of the same material asthat of the first insulating layer is disposed, however, the secondinsulating layer is formed at a temperature lower than that of the firstinsulating layer as in the case of the interlayer insulating layer.Accordingly, the second insulating layer has lower insulating propertythan the first insulating layer. As described above, the insulatingproperty at the intersection portion between the signal wiring and thebias wiring is lower than that at the intersection portion between thesignal wiring and the gate drive wiring.

On the other hand, a reduction in wiring resistance which causes noisein the signal wiring is required. For the wiring resistance, generally,the wiring is formed thick or large in width. However, in the FPDconfigured by arranging the wirings in the matrix, when the wiring isformed large in width, an area at the intersection portion between thewirings becomes large which causes an increase in parasitic capacitance.Thus, the wiring is not formed so large in width. Hence, the wiringresistance is reduced mainly by forming the wiring thick.

However, when the signal wiring is formed thick, it is accompanied by anenlargement of a step and it is difficult to perform microprocessing,which makes it difficult to control a processing form. When the step isenlarged by the signal wiring and the processing form is deteriorated,it is difficult to uniformly form the interlayer insulating filmdisposed by covering the signal wiring. When an inorganic material isused for the interlayer insulating film, it is difficult to form theinterlayer insulating film to be thick. Thus, it is difficult to formthe interlayer insulating film which covers a side surface of the signalwiring to be in similar thickness to that of the surface.

Accordingly, at the intersection portion between the signal wiring andthe bias wiring, insulating property is reduced between the side surfaceof the signal wiring and the bias wiring, thus increasing possibilitiesof leakage and of generation of uneven line images. In other words, wheneach wiring is formed thick for the purpose of reducing noise, leakageoccurs between the wirings. Moreover, prevention of leakage leads toinsufficient improvement in terms of noise.

DISCLOSURE OF THE INVENTION

The present invention has been made to solve the foregoing problems, andhas an object to provide a photoelectric conversion apparatus configuredby stacking photoelectric conversion element layers including aphotoelectric conversion element over a switching element layerincluding a switching element, and a radiation detecting apparatus, forpreventing leakage caused by an intersection portion between wirings andsuppressing noise. Thereby a high S/N ratio can be obtained.Accordingly, image information of high image quality can be obtained.

A conversion apparatus and a radiation detecting apparatus according tothe present invention includes: an insulating substrate; a pixel regionincluding a switching element region in which a plurality of switchingelements each including a first metal layer disposed over the insulatingsubstrate, an insulating layer disposed over the metal layer, a firstsemiconductor layer, and a second metal layer are arranged in row andcolumn directions,

a conversion element region in which a plurality of conversion elementseach including a lower electrode made of a third metal layer disposedover the switching element region, a second semiconductor layer disposedover the lower electrode, and an upper electrode made of a fourth metallayer disposed over the second semiconductor layer are arranged in rowand column directions, and each pixels including the switching elementsand the conversion elements; a plurality of signal wirings including thesecond metal layer, signal wirings being connected to the plurality ofswitching elements of the column direction; a plurality of bias wiringsincluding the fourth metal layer, bias wirings being connected to theplurality of conversion elements; and an external signal wiring portionincluding the first metal layer outside the pixel region, the externalsignal wiring portion being connected to the signal wirings, in whichthe external signal wiring portion and the bias wiring intersect eachother.

The conversion apparatus and the radiation detecting apparatus of thepresent invention includes a pixel region including a switching elementincluding a first metal layer disposed over an insulating substrate, aninsulating layer disposed over the first metal layer, a firstsemiconductor layer, and a second metal layer, a conversion elementincluding a lower electrode made of a third metal layer disposed overthe switching element, a second semiconductor layer disposed over thelower electrode, and a fourth metal layer disposed over the secondsemiconductor layer, and a plurality of pixels including the switchingelements and the conversion elements in row and column directions,signal wirings connected to the plurality of switching elements of thecolumn direction, and bias wirings connected to the plurality ofconversion elements. At intersection portions between the signal wiringsand the bias wirings, each signal wiring is including the first metallayer, and each bias wiring is including the fourth metal layer.

According to the present invention, high insulating property is securedat the intersection portion between the signal wiring and the biaswiring outside the pixel region. And thus capacitance between the signalwiring and the bias wiring which becomes parasitic capacitance of thesignal wiring is reduced. Whereby noises added to signal charges can besuppressed and an image signal of a high S/N ratio can be obtained.Thus, it is possible to obtain image information of high image quality.Moreover, thick signal wirings can be disposed and wiring resistance ofthe signal wirings is reduced, whereby it is possible to improvesensitivities of the photoelectric conversion apparatus and theradiation detecting apparatus.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention.

FIG. 1 is a conceptual plan diagram of a photoelectric conversionapparatus and a radiation detecting apparatus according to the presentinvention;

FIG. 2 is a conceptual plan diagram in which an area A of aphotoelectric conversion apparatus and a radiation detecting apparatusis enlarged according to a first embodiment;

FIG. 3 is a schematic sectional diagram of the photoelectric conversionapparatus and the radiation detecting apparatus according to the firstembodiment;

FIG. 4 is a conceptual sectional diagram showing another example of aphotoelectric conversion apparatus and a radiation detecting apparatusof the present invention;

FIG. 5 is an explanatory diagram showing application of a radiationdetecting apparatus to a radiation detecting system of the presentinvention;

FIG. 6 is a conceptual plan diagram showing a conventional photoelectricconversion apparatus and a conventional radiation detecting apparatus;

FIG. 7 is a conceptual plan diagram showing one pixel of theconventional photoelectric conversion apparatus and the conventionalradiation detecting apparatus; and

FIG. 8 is a conceptual sectional diagram showing the conventionalphotoelectric conversion apparatus and the conventional radiationdetecting apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

The best modes for carrying out the present invention will be describedbelow in detail with reference to the drawings.

First Embodiment

Referring to FIGS. 1 to 3, a first embodiment of the present inventionwill be described in detail.

FIG. 1 is a conceptual plan diagram showing a photoelectric conversionapparatus and a radiation detecting apparatus according to the firstembodiment of the present invention. FIG. 2 is a conceptual plan diagramof the enlarged area A of FIG. 1. FIG. 3 is a schematic sectionaldiagram taken on the line 3-3 of FIG. 2. In FIGS. 1 to 3, the samecomponents as those of the conventional FPD shown in FIGS. 6 to 8 willbe denoted by the same reference numerals, and detailed descriptionthereof will be omitted.

In FIGS. 1 to 3, reference numeral 100 denotes an insulating substrate,101 a photoelectric conversion element which is a conversion element,102 a switching element, 103 a drive wiring, 104 a signal wiring, and105 a bias wiring. For the insulating substrate 100, a glass substrate,a quartz substrate, a plastic substrate or the like is suitably used.The photoelectric conversion element 101 is an MIS type photosensor madeof a-Si, the switching element is a TFT made of a-Si, and thephotoelectric conversion element 101 and the switching element 102constitute one pixel. Such pixels are arranged in a 2-dimensional matrixto constitute a pixel region P. The drive wiring 103 is a wiringconnected to gate electrodes 110 of a plurality of switching elements102 arrayed in a row direction, and formed of a first metal layer M1which is the same layer as that of the gate electrodes 110 of theswitching elements 102. The signal wiring 104 is a wiring connected tosource or drain electrodes 114 of a plurality of switching elements 102arrayed in a column direction, and formed of a second metal layer M2which is the same layer as that of the source or drain electrodes 114 ofthe switching elements. The bias wiring 105 is a wiring connected to anupper electrode layer 120 to apply a bias to the photoelectricconversion element 101, thereby constituting a sensor upper electrode,and formed of a fourth metal layer M4 made of a metallic material suchas Al. In FIG. 2, to simplify the drawing, first to second insulatinglayers 111 to 117 are omitted.

According to the first embodiment of the present invention, referencesymbol 103 a denotes a drive wiring drawing portion connected to eachdrive wiring 103 via a contact hole 126 outside the pixel region P. Thedrive wiring drawing portion 103 a includes a drive wiring terminal 123disposed to electrically connect with a drive circuit 107. The drivewiring drawing portion 103 a and the drive wiring terminal 123 areformed of a fourth metal layer M4 which is the same layer as that of thebias wiring 105 as an uppermost metal layer in an FPD of a laminatedstructure. Accordingly, because of a structure in which there is only aprotective layer 121 on a drive wiring terminal 123, an opening forelectrical connection with the drive circuit 107 is easily formed.Because the drive wiring drawing portion 103 a and the drive wiringterminal 123 are formed of the same fourth metal layer M4 as that of thebias wiring 105, as in the case of the bias wiring 105, the surfacethereof is covered with an upper electrode layer 120. Thus, it ispossible to prevent corrosion of the fourth metal layer M4 in the drivewiring terminal 123.

Reference symbol 104 a denotes a first signal wiring drawing portionconnected to each signal wiring 104 via a contact hole 127 outside thepixel region P. The first signal wiring drawing portion 104 a isconnected to a second signal wiring drawing portion 104 b via a contacthole 128. Further the second signal wiring drawing portion includes asignal wiring terminal 124 disposed to electrically connect with asignal processing circuit 106. Here, the first signal wiring drawingportion 104 a is formed of the first metal layer M1 as in the case ofthe drive wiring 103. The second signal wiring drawing portion 104 b andthe signal wiring terminal 124 are formed of the fourth metal layer M4which is the same layer as that of the bias wiring 105 as an uppermostmetal layer in the FPD of the laminated structure. Accordingly, becauseof a structure in which there is only a protective layer 121 on thesignal wiring terminal 124, an opening for electrical connection withthe signal processing circuit 106 is easily formed. Because the secondsignal wiring drawing portion 104 b and the signal wiring terminal 124are formed of the same fourth metal layer M4 as that of the bias wiring105, as in the case of the bias wiring 105, the surface thereof iscovered with the upper electrode layer 120. Thus, it is possible toprevent corrosion of the fourth metal layer M4 in the signal wiringterminal 124.

Next, the bias wiring 105 includes a bias wiring terminal 125 disposedto electrically connect with a bias power source unit 109. In this case,the bias wiring terminal 125 is constituted of a fourth metal layer M4which is the same layer as that of the bias wiring 105 as an uppermostmetal layer in the FPD of the laminated structure. Accordingly, becauseof a structure where there is only a protective layer 121 on the biaswiring terminal 125, an opening for electrical connection with the biaspower source unit 109 is easily formed. Because the bias wiring terminal125 is constituted of the same fourth metal layer M4 as that of the biaswiring 105, the surface is covered with the upper electrode layer 120,as in the case of the bias wiring 105. Thus, it is possible to preventcorrosion of the fourth metal layer M4 in the bias wiring terminal 125.

Next, referring to FIG. 3, a sectional structure of the signal wiring104 and the first signal wiring drawing unit 104 a at the contact 127, asectional structure of the first signal wiring drawing unit 104 a andthe second signal wiring drawing 104 b at the contact 128, and asectional structure of the bias wiring 105 and the first signal wiringdrawing unit 104 a at the intersection C3 will be described in detail.

In FIG. 3, reference numeral 111 denotes a first insulating layer, 112 afirst semiconductor layer which is a layer identical to an active layerof the switching element 102, 113 a first impurity semiconductor layerwhich is a layer identical to an ohmic contact layer of the switchingelement 102, and 115 an interlayer insulating layer. Reference numeral116 denotes a third metal layer M3 which is the same layer as a sensorlower electrode, 117 a second insulating layer which is a layeridentical to an insulating layer of an MIS type photosensor, 118 asecond semiconductor layer which is a layer identical to a photoelectricconversion layer of the MIS type photosensor, 119 a second impuritysemiconductor layer which is a layer identical to an ohmic contact layerof the MIS type photosensor, 120 a transparent electrode layer which isa layer identical to the upper electrode layer of the MIS typephotosensor, and 121 a protective layer. In this case, a wavelengthconverter 122 is omitted.

In FIG. 3, the contact 127 is provided by boring an opening in the firstinsulating layer 111. Accordingly, the signal wiring drawing unit 104 aconstituted of the first metal layer M1 and the signal wiring 104constituted of the second metal layer M2 are electrically connected toeach other. The contact 128 is provided by boring an opening in thefirst insulating layer 111, the first semiconductor layer 112, the firstimpurity semiconductor layer 113, the interlayer insulating layer 115,the second insulating layer 117, the second semiconductor layer 118, andthe second impurity semiconductor layer 119, and via the third metallayer 116. Accordingly, the first signal wiring drawing unit 104 aconstituted of the first metal layer M1 and the second signal wiringdrawing unit 104 b constituted of the fourth metal layer M4 areelectrically connected to each other. The intersection C3 is insulatedbetween the first signal wiring drawing unit 104 a constituted of thefirst metal layer M1 and the bias wiring 105 constituted of the fourthmetal layer M4 via the first insulating layer 111, the firstsemiconductor layer 112, the first impurity semiconductor layer 113, theinterlayer insulating layer 115, the second insulating layer 117, thesecond semiconductor layer 118, and the second impurity semiconductorlayer 119. As in the case of the other intersections C1 and C2, theintersection C3 of the present invention is insulated via the firstinsulating layer 111 which becomes a gate insulating film of theswitching element 102. Because this first insulating layer 111 is usedas a gate insulating film of the switching element 102, one having a lowdielectric constant, large resistance, and high insulation performanceis used. Accordingly, by providing the first insulating layer 111 havinga low dielectric constant and high insulation performance at theintersection C3, it is possible to reduce parasitic capacitance and toprevent leakage between the wirings. Moreover, there are moreinterpolated layers as compared with the conventional intersection C3,and accordingly a distance can be increased between the first biaswiring drawing unit 105 a and the signal wiring drawing unit 104 a.Thus, it is possible to further reduce the parasitic capacitance.

In this embodiment, the case of the MIS type FPD of the laminatedstructure which uses the MIS type photosensor as the photoelectricconversion element 101 has been described. However, for a photoelectricconversion element similar to that shown in FIG. 4, a PIN type FPD thatuses a PIN type photodiode 131 may be used. Reference numeral 130denotes a third impurity semiconductor layer into which conductiveimpurities different from those of the second impurity semiconductorlayer 119 have been introduced. In the PIN type photodiode, an n-typea-Si layer and a p-type a-Si layer are suitably used respectively forthe second impurity semiconductor layer 119 and the third impuritysemiconductor layer 130. In this embodiment, the case where the gapetching type TFT is used as the TFT which is the switching element 102has been described. However, the present invention is not limited tothis. For example, a gap stopper type TFT or a planar type TFT employedby a poly-Si TFT may be used. In other words, when three or more layersof at least the drive wiring 103, the signal wiring 104 and the biaswiring 105 are used in the combination of the switching element 102 andthe photoelectric conversion element 101, improvements can be madeaccording to the present invention. According to the embodiment, thesignal wiring 104 and the source or drain electrode 114, and the sensorlower electrode are formed by using different metal layers, i.e., thesecond metal layer M2 and the third metal layer M3 respectively.However, the present invention is not limited to this. The signal wiring104, the source or drain electrode 114, and the sensor lower electrode(third metal layer) 116 may be formed by using identical metal layers.In this case, however, the signal wiring 104 and the sensor lowerelectrode cannot be stacked on each other, and the photoelectricconversion element cannot be completely stacked on the switchingelement. Thus, a numerical aperture of the FPD is lower as compared withthat of the FPD formed by using different metal layers. In theembodiment, the case of the FPD which uses the MIS type photosensor 101using the second semiconductor layer 118 made of a-Si or the PIN typephotodiode as the conversion element has been described. However, thepresent invention is not limited to this. An FPD that uses a-Se or CdTefor a second semiconductor layer as a conversion element, and aconversion element for directly converting radioactive rays into chargesmay be used. According to the embodiment, the contact 128 is constitutedof one opening. However, the present invention is not limited to this.For example, two openings are prepared, and the first signal wiringdrawing unit 104 a constituted of the first metal layer M1 and thesecond metal layer M2 are electrically connected to each other throughthe first opening disposed in the first insulating layer. Additionally,the second metal layer M2 and the second signal wiring drawing unit 104b constituted of the fourth metal layer M4 are electrically connected toeach other through the second opening disposed in a different region andin the interlayer insulating layer 115, the second insulating layer 117,the second semiconductor layer 118, and the second impuritysemiconductor layer 119.

With this structure, unevenness of each opening and the contacts becomessmall, thereby making it possible to suppress the forming areas ofopenings and contacts. This structure is effective in cases whereunevenness of opening and contacts become large such as a case where aninterlayer insulating layer 115 formed of an organic insulating materialis made thick, or the film of the second semiconductor layer 118 is madethick in order to improve photoelectric conversion efficiency.

According to the embodiment, as shown in FIG. 3, the first insulatinglayer 111 alone is arranged between the drive wiring 103 constituted ofthe first metal layer M1 and the signal wiring 104 constituted of thesecond metal layer M2. However, the present invention is not limited tothis. The first insulating layer 111, the first semiconductor layer 112,and the first impurity semiconductor layer 113 may be arranged betweenthe drive wiring 103 and the signal wiring 104. Further, according tothe embodiment, the bias wiring 105 constituted of the fourth metallayer M4 and the second signal wiring drawing unit 104 b are arranged onthe second insulating layer 117. However, the present invention is notlimited to this. The second semiconductor layer 118, the second impuritysemiconductor layer 119, or the third impurity semiconductor layer 130may be arranged between the second insulating layer 117 and the biaswiring 105 or the second signal wiring drawing unit 104 b. It isgenerally known that the layer configuration between the wirings ischanged by the element forming process, and this is in no way limitativeof the present invention.

Second Embodiment Application Example

FIG. 5 shows an application example of an X-ray diagnosis system whichuses the FPD type radiation detecting apparatus of the presentinvention.

An X-ray 6060 emitted from an X-ray tube 6050 is transmitted through abreast 6062 of a patient or a person to be inspected 6061, and made tobe incident on a radiation detecting apparatus 6040 having ascintillator (fluorescent material) mounted thereon. The incident X-raycontains information on the inside of a body of the patient 6061. Thescintillator emits light corresponding to the entry of the X-ray, andthe light is subjected to photoelectric conversion to obtain electricinformation. This information is converted into digital information,subjected to image processing by an image processor 6070 which becomessignal processing means, and can be observed by a display 6080 whichbecomes display means of a control room.

The image processor 6070 can transfer the electric signal output fromthe image sensor 6040 to a remote place via transmission processingmeans such as a telephone line 6090 to display the electric signal bydisplay means (display) 6081 in a different place such as a doctor room.The electric signal output from the image sensor 6040 is saved inrecording means such as an optical disk, and a doctor at the remoteplace can make diagnosis by using this recording means. The electricsignal can also be recorded in a film 6110 by a film processor 6100which becomes recording means.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the claims.

CAPABLE OF EXPLOITATION IN INDUSTRY

The present invention is used for a photoelectric conversion apparatus,a radioactive ray detection substrate, and a radiation detectingapparatus which are used for a medical diagnosis apparatus, anon-destructive inspection apparatus, and the like.

This application claims priority from Japanese Patent Application Nos.2005-201602 filed on July 11, and 2006-181896 filed Jun. 30, 2006, whichare hereby incorporated by reference herein.

1. A conversion apparatus, comprising: an insulating substrate; a pixelregion including a switching element region in which a plurality ofswitching elements each including a first metal layer disposed over saidinsulating substrate, an insulating layer disposed over said metallayer, a first semiconductor layer, and a second metal layer arearranged in row and column directions, a conversion element region inwhich a plurality of conversion elements each including a lowerelectrode made of a third metal layer disposed over said switchingelement region, a second semiconductor layer disposed over said lowerelectrode, and an upper electrode made of a fourth metal layer disposedover said second semiconductor layer are arranged in row and columndirections, and each pixels including said switching elements and saidconversion elements; a plurality of signal wirings including said secondmetal layer, and being connected to said plurality of switching elementsof the column direction; a plurality of bias wirings including saidfourth metal layer, and being connected to said plurality of conversionelements; and an external signal wiring portion including said firstmetal layer outside the pixel region, and being connected to said signalwirings, wherein said external signal wiring portion and said biaswiring intersect each other.
 2. A conversion apparatus according toclaim 1, wherein said switching element includes a gate electrodeincluding said first metal layer formed on said insulating substrate,said insulating layer formed on said gate electrode, said firstsemiconductor layer formed on said insulating layer, and a source ordrain electrode including said second metal layer formed on said firstsemiconductor layer.
 3. A conversion apparatus according to claim 2,further comprising an interlayer insulating layer arranged between saidswitching element region and said conversion element region, whereinsaid external signal wiring portion and said bias wiring furtherintersect each other by sandwiching said interlayer insulating layer. 4.A conversion apparatus according to claim 1, wherein said second metallayer and said third metal layer are including identical metal layers.5. A conversion apparatus according to claim 1, further comprising asecond external signal wiring portion including said fourth metal layeroutside said pixel region and connected to said external signal wiringportion.
 6. A conversion apparatus according to claim 1, furthercomprising a plurality of drive wirings including said first metal layerand connected to said plurality of switching elements of the rowdirection, and a external drive wiring portion including said fourthmetal layer outside said pixel region and connected to said drivewirings.
 7. A conversion apparatus according to claim 6, wherein: saidexternal drive wiring portion includes a first terminal; said secondexternal signal wiring portion includes a second terminal; said biaswiring includes a third terminal; a drive circuit is connected to saidfirst terminal to drive said switching element; a signal processingcircuit is connected to said second terminal to process an electricsignal converted by said conversion element; and a bias power sourcepart is connected to said third terminal to apply a bias to saidconversion element.
 8. A conversion apparatus according to claim 1,wherein said conversion element is a photoelectric conversion element.9. A conversion apparatus according to claim 8, wherein saidphotoelectric conversion element is a photoelectric conversion elementfurther including a second insulating layer arranged between said lowerelectrode and said second semiconductor layer, and a second impuritysemiconductor layer arranged between said second semiconductor layer andsaid upper electrode.
 10. A conversion apparatus according to claim 9,wherein said photoelectric conversion element further includes a secondimpurity semiconductor layer arranged between said lower electrode andsaid second semiconductor layer, and a third impurity semiconductorlayer arranged between said second semiconductor layer and said upperelectrode.
 11. A conversion apparatus according to claim 1, wherein saidfirst semiconductor layer and said second semiconductor layer are madeof amorphous silicon.
 12. A radiation detecting apparatus, comprising:the conversion apparatus according to claim 1; and a wavelengthconverter arranged on said conversion element layer, for converting anincident radioactive ray into visible light.
 13. A radiation detectingsystem, comprising: the radiation detecting apparatus according to claim12; signal processing means for processing a signal from said radiationdetecting apparatus; recording means for recording a signal from saidsignal processing means; display means for displaying the signal fromsaid signal processing means; transmission processing means fortransmitting the signal from said signal processing means; and aradioactive ray source for generating radioactive rays.
 14. A conversionapparatus comprising: an insulating substrate; a pixel region includinga plurality of pixels in row and column directions, each pixel includinga switching element including a first metal layer formed on saidinsulating substrate, an insulating layer formed on said first metallayer, a first semiconductor layer, and a second metal layer, and aconversion element including a lower electrode made of a third metallayer formed on said switching element, a second semiconductor layerformed on said lower electrode, and an upper electrode made of a fourthmetal layer disposed over said second semiconductor layer; signalwirings connected to said plurality of switching elements of the columndirection; and bias wirings connected to said plurality of conversionelements; wherein at an intersection portion between said signal wiringand said bias wiring, said signal wiring is including said first metallayer, and said bias wiring is including the first said fourth metallayer.